Power transmission apparatus



May 30, 1950 H. F. HO BBS POWER TRANSMISSION APPARATUS 2 Sheets-Sheet 1 Filed Dec. 10, 1946 IHVEH 102 How an Hams/1m Hams 2/9015 w W May 30, 1950 H. F. HOBBS 2,509,820

POWER TRANSMISSION APPARATUS Filed Dec. 10, 1946 i 2 Sheets-Sheet 2 luvsmoa HOWARD Peas/21m Hoaas s-/ ya Wig {W Patented May 30, 1950 STATES PATENT eesi PGWER? 'ERA-NSMIS SIGN Howard-Frederick Hobbs, heamingtom Spa; Ene-- land assignoxitolflnbbs Eransmissiom Limited; London, England; a British comnaml Applieatibnifl'ecember 10, 1 94 6, SerialNdflsliZflB:

'In Great Britain Dee'emh Hamil-19% This invention relates to power: mansmission annanaitus and its; main object is-toi oroviid'e 'an improved form -ofkepicyeliorgeaning, .i-. e-.. "gearing ofr the type; comprisirrg -atoothedsumwheel; a "seeundi-toothedelement,v hinions insgean -w.ith-.-the a,

sm-Wheel and ioperatively eonnectedtwith' the seeondmoothed element, a: eageicasrying the pin:-

=inns,;-and means for holding-1 fneeing; and driving thee various pants to: obtain. requinedytnansmission "ratios, :Thewgearingrmay be p1anetaryand Am diifieitential.

' According to: the invention-an apparatus which pmvides different natios byhdlding, freeing, and drivingvarious parts includes-am .epieyelic; gear comprising; a sum-WheeL; a number ofipla-net pinions in gee-1 with-thesun-Wheehai cage: enemy :ingzthez spindles of s-aidip 11110115; ,a toothedgear-op- 'snaz-tinelyeonneeted with said pinienss, and. output shaft, meanswhich opevatively con-neat the out,-

nitt. sha'fttoiona of: theselements otthet gean train dating: operation in onewtransmission natie and whichoperatively" conneet xotltputt shaftto another." of said; elements mining operation in @amntherratioiandmeans-for holding the two-relements otthe gear tnaini thus,engageaibletnelatinely stationary-whilst the gear' train is::stil1.,-trans mi-t!- ting powerwhen it is magnifiedto; disenga the mate; .eiement and engage the other...

fine form oftheaini/entiom wilhnowbe descnihed bywayof" examplewith nefierencetm the aeeom panning drawings wherein:

Eisure: 1 is; a vertical sectional; view ot the fasont hart ot an apparatus made-in accordance the invention; and:

2c'is ai'vertieafliseetional view ot. the rear ,gantstof thesame apparatus The apparatns has an input shatt or 1 en ine ingthe mltpnt shaimzare two eoneentrie sleeves 33; k :whiehseizve as reactionshaf-tsa,

input aha-fit I ea riedahousingi in. which iii-mete clutch presser: rings: 14-,v 13- 132 aremounted.

lrsessin'e applied to, thesesings engagesefnietion "clutch-plates 6!, 1 ;8 nespeettvely. The-housing 5 eontainsthree. fiexi-hlediaphnagmsfi, Ht, I htomne same; of: eaeh oh which.fluidundenpressmae; can-be admitted froma pump: Mandi a. GQILtDOh-\t&l8-33 :amtsuitable. ducts such-ask 303,, 2 L 3t, 32-.

A eentritugally balanced pnessu-ne emanated spring: pressed valveli: is associated-with eaeh maphnagmend these serve! to; either'onen a duct as 21 to the diaphragm throushduets such ss-n; or-to: onemthe diaphragm to exhaust through: theerduets. zasandl exhausthheles 16; A spring as urges? the valvel'outwaxds amtshould the eluteh: faoings.

pressures-be removedsimm: the-duet 2&1! by anemition "of thewame 33,, themalve 25 willzmoaeocutr wandsand exhaustethe-roilsfnomi behind the. diet.- ephragmt. .Ifpnessuseis directexiz fhonnthevalvafi tosthezdnetzd itwiliaet-huponi-thelauteir; end, theMaLve- 25eai1sin -to. move inwards. fimings -15: sews ta press the, pressen sings; tcwvs'isclst the .dlesigned' pesitionv :The pasts ofithe seam ess arranged so that oil for lubrication fed Marthe .eeicyelie geantminsheneinafiiek1Z0? be, describe meshes the insideldiametensiofvthe-hresser Ii-Slates;

When the clutches are disengaged the oiL-passes outwards; through. gnomes in; the ,pnessez: plates, one ST 111iE'IQGMQQQwbQiIIg-SIIOWIL; Insulator plates 35 separate the presser plates from nthewdia ulna-ems the elutchesaile diseneaeedithe presses, plate.- abutsagainstthe pant of the Imus;- ing ini'wiiieh thesdiaphragmstane located and, the evil .eannotthen easily reach the emote-sand. same of: it, passes. over the, pnesser; plates. andtreashes Thfit lubricating; oiL sup,- fsem the pump: bymeansoiwdnill'ingse to. the

passes tolnhrieate the gearinaanditheclutchs The: nun-pose of. lubxzieating the: chiteheshis-it gm, videa smoothness in-,-take u-QI'QM to pnenentw err-the: faeingsat Suitable drilling-s.v are shown; on the drawings at 3a and,

A planetary difierential epicyclic gear pm,- vide'd: which ineludes a; cage; .22 which is, minimized on the neaetien. shaft. 3 v and canines, the eluteh plate: 1 The-cage ineludeswbeaningsv-zlas which carry the spindles 2| oira setrot. donblepinions tfiiulbnfi different size- Ehepinions t6, of

weaehypain. aseinte nally cenneoted: andithesmaller pinions l6 gear witha .sunrwheel Lakshmi- 1 s larger pinions i? ate in gear. withateeth 21L constituting-a seeonct sunswheelz tormedonvthelreaer .tienal bzzakeu andiof abieaxing 45.. vThereaetiqn brakesare of smiles-construction in the; clutches and comprise the presser plates 40, 4|, the insulator plates 46, 41 and the diaphragms 43, 42 carried by the stationary side plates 42a and 43a. A common spring 31 serves to disengage the presser plates and to hold them against an abutment so that lubricating oil fed from holes in the sleeve 3, 4 will be diverted to the friction surfaces, When the brakes are in the engaged condition the oil will pass between the presser plates and the insulator plates as previously described in connection with the clutches. Air will also be drawn either on the one side or the other of the presser plate according to whether the brake is engaged or disengaged. This tends to cool the parts and also to carry the oil in the desired directions.

The apparatus described provides a reverse ratio, three forward indirect ratios, a direct ratio and an overdrive. The various ratios are obtained as follows:

First ratio is obtained with the output shaft moved to its rearward position so as to engage the sun-wheel I9, by engaging the clutch 6 and brake 38. Reaction torque is imparted through the sleeve 4 and this is largely carried by the brake 44. The brake 38 will be insufficiently large to carry the full over-run reaction torque, so that should the brake be engaged with the gear running at high speed no damage or shock will result.

Second speed is obtained by disengaging clutch 6 and engaging clutch 1. Brake 38 will remain engaged.

Third speed will be obtained by disengaging clutch I and brake 38 and engaging clutch 8 and brake 39.

Fourth speed, direct, is obtained by disengaging the brake 39 and engaging the clutches 8, I, together, or if desired, 8, 'l, 8 together. Whilst operating in this condition the output shaft can be moved forward so, as to disengage the sun-wheel l9 and engage the teeth on the disc carrying the ring gear i8, the sun-wheel and the ring gear being relatively stationary. With the ring gear engaging the output shaft 2, the clutch I will be left engaged and 8 and 9 disengaged and the reaction brake 38 applied. This gives fifth speed which is an overdrive the output shaft 2 being driven at greater speed than that of the input shaft l.

Reverse is obtained with the output shaft in the forward position, i. e. in engagement with the ring gear [8 and for reverse the clutch 8 and the brake 38 are engaged.

If only the clutches l and 8 are provided four speeds are obtainable; this can be effected merely by removing the clutch plate 6.

The sleeve 3 which carries the brake 39 may also be provided with a dog clutch at its rear end to assist the brake 39 to carry the reaction torque during reverse ratio drive. The shaft 2 may be operated by means of an hydraulic piston working within a cylinder and the oil pressure may be led to one end or the other from the valve 33. V Instead of the output shaft 2 being provided with teeth to engage either the sun-wheel or ring gear, the sun-wheel and ring gear may both be mounted upon the shaft, but spaced sufficiently so that movement of the shaft will engage either the sun-wheel with the pinions or the ring gear with the pinions.

' It will be clear that the invention may be applied in various other forms, for example the output shaft 2 may engage either the cage or the ring gear; alternatively the cage of the sunwheel. There may be but a single set of pinions and a simple epicyclic train may provide a reduced ratio, a direct ratio and an increased ratio by driving or holding one or the other elements and by engagement of the output shaft as already described.

The output shaft could carry two toothed annuli for engaging the teeth 23, 24 respectively.

I claim:

1. A power transmission comprising an input shaft, a housing carried by said input shaft, fluid pressure operated means carried by said housing, an axially movable output shaft, inner and outer reaction shafts concentric with the output shaft, brake means associated with each reaction shaft, a first friction clutch member carried by the outer shaft, an epicyclic gear train having a first sun wheel carried on said outer shaft adjacent said clutch member and a second sun wheel with inner teeth thereon, a cage mounted on the inner reaction shaft and carrying a second friction clutch member, duplex pinions carried by the cage, each of said duplex pinions consisting of a small and a larger pinion fixed to ether, said larger pinions being engageable with the sun wheel mounted on the outer reaction shaft and said small pinions being engageable with the second sun wheel, a ring gear carrying a third clutch member and engageable with the small pinions, a disc member having inner gear teeth and supporting the ring gear, teeth on the output shaft selectively engageable with the inner teeth of the disc member or the second sun wheel when said output shaft is moved axially, and selective means for said fluid pressure operated means for selectively engaging said clutch members.

2. A power transmission comprising an input shaft, a housing carried by said input shaft, fluid pressure operated means carried by said housing, an output shaft, inner and outer reaction shafts, brake means associated with each reaction shaft, a clutch member carried by the outer reaction shaft, a multiple number of duplex planet pinions, each duplex pinion comprising a large and a small gear, a cage carrying said duplex pinions mounted on the inner reaction shaft, a second clutch member mounted on the cage, gear means on the outer reaction shaft engageable with one of the gears of each of said duplex pinions, a second gear means engageable with the other gears of each of said duplex pinions, a ring gear engageable with the said other gears of each of said duplex pinions, means for selectively clutching the output shaft with either the ring gear or the second gear means and selective means for said fluid pressure operated means for selectively engaging said clutch members.

3. A power transmission comprising an input shaft, a housing carried by said input shaft, fluid pressure operated means carried by said housing, an output shaft, inner and outer reaction shafts, brake means associated with each reaction shaft, a clutch member carried by the outer reaction shaft, a multiple number of duplex planet pinions each pinion, comprising a large and a small gear a cage carrying said duplex pinions mounted on the inner reaction shaft, a second clutch member mounted on the cage, gear means on the outer reaction shaft engageable with one of the gears of each of said duplex pinions, a second gear means engageable with the other gears of each of said duplex pinions, a ring gear engageable with said other gears of each of said duplex pinions, means for selectively clutching the output shaft with either the ring gear or the second gear means, and selective means for said fluid pressure operated means for selectively engaging said clutch members thereby providing a first drive ratio when the second clutch member and the outer reaction shaft brake means are engaged and the output shaft is engaged with the second gear means, a second drive ratio when the first clutch member and the inner reaction shaft brake means are engaged and the output shaft is engaged with the second gear means, a third dnive ratio or direct drive when both the clutch members are engaged and the output shaft is engaged with either the ring gear or the second gear means, both the ring gear and the second gear means rotating at the same speed durins direct drive, and a fourth drive ratio when the second clutch member outer reaction shaft brake means are engaged and the output shaft is engaged with the ring gear. 7

4. A power transmission apparatus comprising an input shaft, at least two sets of friction members carried by the input shaft, an epicyclic gear train having sun wheels, a ring gear, a number of double planet pinions in mesh with the sun wheels and the ring gear, spindles carrying the pinions and a cage vcarrying said spindles, two rotary elements, friction lutch means carried by each of said elements, one of the elements also carrying the cage and the other of the elements in mesh with the pinions, brake means associated with each element, an output shaft, teeth on the output shaft, means for selectively clutching the output shaft with either the ring gear or one of the sun wheels, and selective means for engaging said friction members to said clutch means.

5. A power transmission apparatus comprising an input shaft, at least two sets of friction members carried by the input shaft, an epicyclic gear train having sun wheels, a ring gear, a number of duplex planet pinions in mesh with the sun wheels and the ring gear, spindles carrying the pinions and a cage carrying said spindles, two rotary elements, friction clutch means carried by each of said elements and cooperating with said friction members whereby either one or both of said elements can be driven through the clutches at different stages of operation, one of the elements also carrying the cage and the other of the elements carrying one of said sun wheels in mesh with the pinions, brake means associated with each element, an output shaft, teeth on the output shaft, and means for selectively clutching the output shaft with either the ring gear or one of the sun wheels, thereby providing direct drive ratio when both friction clutches are engaged simultaneously, a drive ratio below direct drive 6 when one of the clutches and one of the brake means are engaged and the teeth on the output shaft are engaged with the sun wheel and a drive ratio above direct drive when the other clutch is engaged and the teeth on the output shaft are engaged with the ring gear.

6. A power transmission apparatus comprising an input shaft,at least two sets of friction members carried by the input shaft, an epicyclic gear train having sun wheels, a ring gear, a number of double planet pinions in mesh with the sun wheels and the ring gear, spindles carrying the pinions and a cage carrying said spindles, two rotary elements, friction clutch means carried by each of said elements and cooperating with the friction members whereby either one or both of said elements can be driven through the clutches at different stages of operation, one of the elements also carrying the cage and the other of the elements carrying one of said sun wheels in mesh with the pinions, brake means associated with each element, an axially movable output shaft, teeth on the output shaft, and means for selectively clutching the output shaft with either the ring gear or one of the sun wheels, thereby providing direct drive ratio when both friction clutches are engaged simultaneously, a drive ratio below direct drive when one of the clutches and one of the brake means are engaged and the teeth on the output shaft are engaged with the sun wheel, and a drive ratio above direct drive when the other clutch is engaged and the teeth on the output shaft are engaged with the ring gear, the'teeth on the axially movable output shaft being engageable with either the sun wheel or the ring gear during direct drive ratio whereby the output shaft may be engaged with that element of the epicyclic gear which is to be used in the next selected ratio.

HOWARD FREDERICK HOBBS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,316,740 Reeve Sept. 23, 1919 2,112,487 Freeborn Mar. 29, 1938 2,351,061 Meyer et a1 June 13, 1944 2,395,459 C'arnagua Feb. 26, 1946 FOREIGN PATENTS Number Country Date 146,668 Great Britain July 15, 1920 7 

